Wouldn't that be a manual focusing Nikkor 800mm then?
I don't think it's cheaper than an A*600, though?

I tried an A* 600 and the purple fringing drove me batty. I have one picture of a hummingbird where the beak (maybe ten or twenty pixels) is nothing but purple.

I don't think manual focus lenses are good for wildlife. I ended up getting the Sigma 300-800 (zoom + AF makes for great wildlife tracking IMO) for $4500 IIRC. My D600 + 24-85 was $2k. I got a grey-market 1.4x TC for $400. That's a lot of stuff for the equivalent of the 560, and a lot better IQ than the 560.

I ended up getting the Sigma 300-800 (zoom + AF makes for great wildlife tracking IMO) for $4500 IIRC. My D600 + 24-85 was $2k. I got a grey-market 1.4x TC for $400. That's a lot of stuff for the equivalent of the 560, and a lot better IQ than the 560.

Huh, the Sigmonster? Over here it's more expensive new than the 560, weighs almost twice as much - and what do you know about the IQ?

Good for you that you're happy with your setup, but the opportunity to buy used third party super tele lenses doesn't seem like the most convincing argument for switching to a FF system...

Nope. But for a 560 + APS-C to be better than a FF + 800mm (even a poor one, which I don't think this lens is) would be close to impossible in practice. We'll see when the 560 comes out, but with it's low-glass design I'm not expecting it to be fantastic.

Huh, the Sigmonster? Over here it's more expensive new than the 560, weighs almost twice as much - and what do you know about the IQ?

It is heavy, that's for sure. I'm not going to handhold it. If you want to hand-hold it then you don't want this lens. I personally wouldn't handhold the 560 though either, so the extra weight was more-or-less moot to me. I'm not hiking with it for more than a mile or two, ever, and it's basically it's own backpack. The worst thing about this lens is the MFD which is on par with the 560, so magnification ends up being ~40% better.

Originally posted by gazonk

Good for you that you're happy with your setup, but the opportunity to buy used third party super tele lenses doesn't seem like the most convincing argument for switching to a FF system...

I don't think, in general, it's a good reason to switch to FF, but the 'free' camera (whether D7000 or D600) and 'free' 24-85 certainly helped convince me. I wanted a longer lens than the DA*300mm, and this setup gave me far, far more flexibility than the 560. I don't want to over-impugn the 560 but I don't understand the target market at all.

Before I get killed, I'm still a Pentax fanboy, FWIW. As soon as they announce the FF I'm pre-ordering it. But that doesn't mean I'm going to agree with all their lens decisions.

In other words, you've made up the Sigma combo having a lot better IQ than the Pentax. I don't care about your expectations, since they're based on thin air.

Actually, I based it on my previous lens testing of actual performance vs. theoretical lens ideals, and my experience choosing/using lenses in the lab, etc. Feel free to discount it of course, I'm not a lens designer by a LONG stretch, but I have a bit more experience with actual performance of lenses than the average person (or photographer) off the street.

If you'd like to do some back-of-the-envelope-research yourself - take a look at the BEST 500mm stuff out there - and figure out how much degradation from best the 800mm would have to be for the 560mm to be better than 800mm. We're talking an increase of 43% of length, which in my experience is far more than the difference between a perfect lens and a mediocre lens.

I've seen a few general pic examples with the the 560, but... We'll never really know until it hits consumers for real testing.

But based upon design specs, optics and all - that there are three existing Sigma PK lens which clearly outperform the 560... The 300 is clearly better as is the 500. And that's sad given what Pentax is expecting consumers to pay for the 560

I can see where eljamoquio is coming from. I went with a D7000 and 300 f4 plus 1.4 TC for just under 2800. If I had upgraded my k 20 to a k5II and bought a DA*300 I would have come in 8 bucks shy of 2600 and STILL not had a TC. . The 300 f4 is an fx lens and has a 5 year warranty. The 200 bucks more is worth it to me and if I go to FX later, I won't have to buy a new lens. That is brand new gear too, not used.

I'm keeping my k20 and wide limited lenses till the body dies. We'll see where Pentax is when that day comes, but I doubt we will be much further along.

Pentax is trying but life is too short to keep waiting, and I've pretty much given up on waiting.

But based upon design specs, optics and all - that there are three existing Sigma PK lens which clearly outperform the 560... The 300 is clearly better as is the 500. And that's sad given what Pentax is expecting consumers to pay for the 560

How do you know that? Counting the elements, comparing a telephoto with a long lens design? Looking at the brand name, and deciding Pentax can't do a good lens, even if they did that, countless times? Because you simply "know" Sigma "is" better?

Originally posted by ElJamoquio

Actually, I based it on my previous lens testing of actual performance vs. theoretical lens ideals, and my experience choosing/using lenses in the lab, etc. Feel free to discount it of course, I'm not a lens designer by a LONG stretch, but I have a bit more experience with actual performance of lenses than the average person (or photographer) off the street.

If you'd like to do some back-of-the-envelope-research yourself - take a look at the BEST 500mm stuff out there - and figure out how much degradation from best the 800mm would have to be for the 560mm to be better than 800mm. We're talking an increase of 43% of length, which in my experience is far more than the difference between a perfect lens and a mediocre lens.

That looks like using thin air to justify evaluating an unknown lens' performance. Sorry, I don't buy that; I still believe it's not over until the fat lady things (i.e. we have samples).

And next paragraph, do I spot a strawman? I never said the 560mm on an APS-C camera is better than an 800mm on a D600. It's you who claimed the latter is a lot better, it's you who claimed you don't expect the former to be "fantastic", without having a clue about how the Pentax lens performs.

By the way, that 43%, while mathematically correct, it's just the most inflated figure you could think of (pushing the discussion on the theoretical domain, to compensate for the D600 low-ish resolution?). The difference in focal length is more than taken care of by the crop factor, and, if the 560mm will manage to outresolve the sensor (likely IMO), we should see no image degradation.
I would not be surprised if the K-5 IIs + 560mm would be a very sharp combination. It's not like all the odds are against it; the lack of an AA filter, the simpler, non-telephoto design, prime vs. zoom... we'll see if the "a lot better IQ" claim stands, when the samples are out.